The brain and thyroid gland work together to create our thyroid hormones, and when working harmoniously and in-sync, provides the foundation for the healthy metabolism of most organ systems in the body. Basically… you are sure to know if your thyroid isn’t working optimally!
Thyroid hormone secretion is tightly regulated by the hypothalamic-pituitary-thyroid axis, where Thyrotropin-releasing hormones is released from the hypothalamus, triggering a chain of events from the production of Thyroid-Stimulating-Hormone (TSH), to the synthesis and secretion of thyroxine (T4) and the subsequent conversion to triiodothyronine (T3) – our active, bioavailable thyroid hormones.
What is the Thyroid Gland?
The thyroid gland is a small structure of two lobes situated at the lower end of the throat, lying along the windpipe below the larynx. Its function is to take iodine from food and the amino acid tyrosine, to make T4 and T3 which are released into the blood stream where they control metabolism.
The thyroid works on a negative feedback loop with the pituitary gland located in the hypothalamus, this means that when low levels of circulating thyroid hormone are detected by the brain, the pituitary gland will increase the production of thyroid stimulating hormone. This is how thyroid disease is detected, when TSH levels appear elevated in blood tests.
Factors That Can Influence Thyroid Function:
- Auto-Immune disease
- Hormone levels
- Nutritional deficiencies
- Environmental toxins
- Parasites/Gut Dysbiosis
- Low-Carb diets
- Vitamin D levels (associated with auto-immune conditions)
- Gluten sensitivity
- Goitrogenic foods (eaten in excess or raw ie. Cauliflower, broccoli, kale, soy)
What Nutrients does the Thyroid Require?
One of the most essential nutrients involved in thyroid hormone production, people deficient in this mineral could be at risk of having an under-active thyroid, commonly known as hypothyroidism. It is actually quite common to be deficient these days, as levels have diminished from our soil in more developed countries so people must obtain iodine through fortified food sources, although it is naturally found in seafood such as seaweed, molluscs and fish.
Selenium both acts to switch on thyroid hormones and exert antioxidant benefits that can protect the thyroid from external damage incurred from free radicals. Although you can easily supplement, selenium is abundant in brazil nuts, sardines and eggs.
Zinc is one of the most utilized nutrients in the body, required for so many important enzymatic reactions and also to help activate thyroid hormones in a similar manner to Selenium. Research also shows that zinc may be involved in TSH regulation - another reason to incorporate zinc-rich foods such as oysters, shellfish, beef, and chicken into your diet.
Iron is also critical to thyroid function and is required for conversion of T4 to T3.
Common Foods That Negatively Affect The Thyroid Gland
- Night Shades
This includes vegetables such as tomatoes, potatoes, capsicums and eggplants. Due to their lectin and alkaloid content, these members of the nightshade family can be problematic in people with thyroid issues as they can promote inflammation and potentiate autoimmune conditions.
Gluten-containing grains like wheat, barley and oats contain the component gliadin which can be toxic for some people. Even if you are not diagnosed as coeliac, gluten can affect gut function leading to poor nutrient absorption and inflammation, all of which can put susceptible people at risk of autoimmune conditions such as Hashimotos and Graves.
- Animal/Dairy Milk
Contains high amounts of antigens and saturated fats which promote inflammation, dairy milk also contains elevated levels of certain hormones and proteins that can cause thyroid disruption through an autoimmune response.
- Goitrogenic Foods
Goitrogenic foods are usually those of the Brassica family and include cabbage, cauliflower, kale, broccoli, brussel sprouts etc. Its important to cook these vegetables before consuming them, as they otherwise have the potential to block the thyroids ability to utilize iodine.
What to Eat
- Fish and Seafood
- Iodized Salt
We used to get a lot of our iodine through our fruit and vegetables, but our soil has become so depleted in this essential mineral that fortification of salt is a great way to increase iodine intake in our modern world.
- Fermented Foods
Fermented foods like yoghurt, sauerkraut, kefir and the like contain beneficial probiotic bacteria that help the gut repair. The strengthening of gut wall integrity not only has the ability to increase innate immunity but also decrease autoimmune reactions that can lead to thyroid disorders.
- Brazil Nuts
One of the best food sources of Selenium, incorporating Brazil nuts into your diet is a great way to get this important nutrient in a safe and effective way, as Selenium can be toxic in very high supplemental doses.
- Withania somnifera
Although not a food, Withania, otherwise known as ashwagandha is a beautiful Auyrvedic herb that supports thyroid function in a gentle and very safe way.
The Thyroid gland and the hormones it produces is an incredibly complex and intricate system, so working with a qualified health practitioner is imperative when experiencing significant thyroid disease. However due to our current environmental climate which encompasses high stress levels, poor diet and nutrient availability and many other factors, it is important for everyone to keep on top of their thyroid health and help to support its function. We can do this by ensuring it is well nourished – something we have control over, which is a great and empowering thing!